1. Field of the Invention
This invention relates to a filament winding structure and technique and particularly to one that produces a densely packed and mechanically stable filament winding.
2. Description of Related Art
Many modern weapon systems utilize a launched missile in which guidance information is transferred between it and a firing platform via a data link in the form of an electrical conductor or a fiber optic filament. Present weapon systems employing such techniques include the so-called TOW missile (i.e. Tube launched, Optically tracked, Wire guided missile). In order to provide adequate range for the guided projectile, it is necessary to store a very long length of wire or fiber optic filament within the weapon system. Typically, a winding is provided on a spool which pays out filament at an extremely high rate as the projectile is propelled toward the target.
A number of parameters must be considered in designing a winding of the type used to provide a data link for a guided missile. In order to provide efficient packaging, it is desirable to provide a winding which is dense and compact. Additionally, the winding should be structurally stable to enable it to retain its wound configuration during storage, handling and dispensing, thus eliminating or reducing the necessity of employing adhesives to maintain winding stability. Yet another objective in the design of such windings is to minimize filament payout drag.
Most high speed filament dispensers now in use employ closely spaced precision windings in which each filament turn nests between turns of the previous layer. Because such designs will not maintain regular geometry if wound against a flat radial flange surface, each layer is stepped back several turns at its axial ends from the underlying layer to maintain winding stability. These winding techniques result in tapered winding ends which reduce the volumetric efficiency of the winding. Another disadvantage of some prior art winding techniques is high drag imposed during filament payout since the windings must be displaced in a radially outward direction a significant distance in order to clear other wraps as the filament is withdrawn from the winding.